Method and apparatus for correcting image error in naked-eye three-dimensional (3D) display

ABSTRACT

A method and apparatus for correcting an image error in a naked-eye three-dimensional (3D) display may include controlling a flat-panel display displaying a stripe image, calculating a raster parameter of the naked-eye 3D display based on a captured stripe image, and correcting a stereoscopic image displayed on the naked-eye 3D display based on the calculated raster parameter, wherein the naked-eye 3D display includes the flat-panel display and the raster.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims under 35 U.S.C. § 119 to Chinese PatentApplication No. 201610055821.4 filed on Jan. 27, 2016, in the StateIntellectual Property Office of the People's Republic of China andKorean Patent Application No. 10-2016-0110120 filed on Aug. 29, 2016 inthe Korean Intellectual Property Office, the entire contents of whichare incorporated herein by reference in their entirety.

BACKGROUND

1. Field

At least one example embodiment relates to three-dimensional (3D)display technology and, more particularly, to a method and apparatus forcorrecting an image error in a naked-eye 3D display.

2. Description of the Related Art

A naked-eye three-dimensional (3D) display is technology having beendeveloped in a 3D display technology. The naked-eye 3D display allows auser to view a 3D image without wearing 3D glasses.

The naked-eye 3D display includes a flat-panel display and a raster onthe flat-panel display.

Due to restrictions on accuracy on manufacturing and installation, theraster may have an error. For example, an actual parameter such as astructure and a shape of the raster may differ from a designed value.Among such parameters, a gap may be present between the raster and ascreen of the flat-panel display as the error of the raster.

The error of the rater may cause an occurrence of an error in astereoscopic image displayed on the naked-eye 3D display, which mayaffect a viewing quality.

SUMMARY

In an aspect, there is provided a method of correcting an image error ina naked-eye 3D display, the method including controlling a flat-paneldisplay to display a stripe image, calculating a raster parameter of thenaked-eye 3D display based on a captured stripe image, and correcting astereoscope image displayed on the flat-panel display based on thecalculated raster parameter. The naked-eye 3D display includes theflat-panel display and a raster disposed on the flat-panel display.

A method and apparatus for correcting an image error in a naked-eyethree-dimensional (3D) display is provided.

Some example embodiments relate to a method of correcting an image errorin a naked-eye 3D display.

In some example embodiments, the method may include controlling aflat-panel display displaying a stripe image, calculating a rasterparameter of the naked-eye 3D display based on a captured stripe image,the captured stripe image being displayed after the stripe imagedisplayed on the flat-panel display passes through a raster provided ona surface of the flat-panel display, and correcting a stereoscopic imagedisplayed on the naked-eye 3D display based on the calculated rasterparameter, wherein the naked-eye 3D display includes the flat-paneldisplay and the raster.

An image of each row in the stripe image displayed on the flat-paneldisplay may have a periodic signal of an equal wavelength, and theperiodic signal may have a change in brightness in a wavelength of eachperiod.

S1(x, y) corresponding to the stripe image may satisfy the followingequations:

S1(x,y)=A1*0.5[sin(W_(c)*(x−P1))+1] where x denotes a horizontalcoordinate of a pixel of the stripe image on a screen of the flat-paneldisplay, y denotes a vertical coordinate of the pixel, A1 denotes anamplitude of the stripe image, and P1 denotes an error in the stripeimage; W_(c)=2π/T_(c), T_(c)=(T_(o)*T_(b))/(T_(o)+T_(b)) where T_(b)denotes a sampling period of the raster on the screen of the flat-paneldisplay; T_(min)<T_(o)<M*T_(min) where M is a predetermined or,alternatively, desired constant; andT_(min)=2*D_(v)*tan(A_(m)/2)*P_(m)/R_(m) where D_(v) denotes a viewingdistance of the naked-eye 3D display, A_(m) denotes a horizontal angleof a capturing device used for capturing, P_(m) denotes a number ofpixels in a gap between stripes to be extracted during an imageprocessing, and R_(m) denotes a horizontal pixel resolution of thecapturing device.

The calculating of the raster parameter based on the captured stripeimage may further include rectifying an image including the capturedstripe image and calculating the raster parameter based on the capturedstripe image.

The rectified image and an unrectified image may satisfy the followingequation: u*[x_(s),y_(s),l]^(T)=H*[x_(i),y_(i), l]^(T) where u denotes astandardization factor, P_(i)=[x_(i),y_(i)] is coordinates of apredetermined or, alternatively, desired pixel of the unrectified image,P_(s)=[x_(s),y_(s)] is coordinates of a pixel of the rectified imagecorresponding to the predetermined or, alternatively, desired pixel ofthe unrectified image, and H denotes a homographic transformationmatrix.

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the raster parameter may becalculated based on a stripe image included in the rectified image, thecalculating of the raster parameter may include acquiring at least twoimage rows by performing sampling in the stripe image of the rectifiedimage at preset or, alternatively, desired sampling intervals, acquiringa local period function T_(r)(x; y_(r)) of a signal corresponding to anr^(th) image row acquired through the sampling, wherein, in T_(r)(x;y_(r)), x denotes a horizontal coordinate on the screen of theflat-panel display, y_(r) denotes a vertical coordinate of the r^(th)image row on the screen of the flat-panel display, r is a value of 1through N, and N denotes a total number of image rows acquired throughthe sampling, calculating G_(r)(x; y_(r)) corresponding to a gap betweenthe screen of the flat-panel display and a raster corresponding to ther^(th) image row, G_(r)(x; y_(r)) satisfying the following equations:G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotesa distance between the screen of the flat-panel display and thecapturing device, P_(x) denotes a horizontal raster interval, and Tsr(x;y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and acquiring a gap G(x, y) between theraster and the flat-panel display by performing fitting based on athree-element set {[x_(c), y_(r), G_(r)(x; y_(r))]}, wherein [x_(c),y_(r)] denotes coordinates of a pixel on the screen of the flat-paneldisplay and G_(r)(x; y_(r)) denotes a gap between the screen of theflat-panel display and the raster corresponding to the pixel.

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the calculating of the rasterparameter based on the captured stripe image may include dividing thescreen of the flat-panel display into at least two neighboring gratings{R_(ij)} having the same size, wherein, in R_(ij), i is a value of 1through N_(r) and j is a value of 1 through N_(r), N_(r) denotes anumber of rows of a grating acquired through a division, and N_(c)denotes a number of columns of the grating, calculating a gap G_(ij)between the screen of the flat-panel display and a raster of the gratingusing a predetermined or, alternatively, desired method with respect tothe respective grating R_(ij), G_(ij) being a constant, and calculatinga gap G(x, y) between the flat-panel display and the raster of thenaked-eye 3D display, wherein if [x, y]∈R_(ij), G(x, y) satisfies thefollowing equation: G(x, y)=G_(ij), and the predetermined or,alternatively, desired method includes acquiring at least two image rowsby sampling a stripe image corresponding to the gratings and therectified image at preset or, alternatively, desired sampling intervals,acquiring a local period function T_(r)(x; y_(r)) of a signalcorresponding to an r^(th) image row acquired through the sampling,wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinate on thescreen of the flat-panel display, y_(r) denotes a vertical coordinate ofthe r^(th) image row on the screen of the flat-panel display, r is avalue of 1 through N, and N denotes a total number of image rowsacquired through the sampling, calculating G_(r)(x; y_(r)) correspondingto a distance between the flat-panel display and a raster correspondingto the r^(th) image row, G_(r)(x; y_(r)) satisfying the followingequations: G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) whereD_(cam) denotes a distance between the screen of the flat-panel displayand the capturing device, P_(x) denotes a horizontal raster interval,and Tsr(x; y_(r)) is a period change function for which the capturingdevice performs sampling by penetrating the raster relative to thescreen of the flat-panel display and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and calculating G(x)=Σ_(r=1)^(N)G_(r)(x; y_(r))/N and acquiring G_(ij) by calculating anx-directional average value using G(x).

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the calculating of the rasterparameter based on the captured stripe image may include generating agrating corresponding to a grating center point gradually anditeratively such that all regions on the screen of the flat-paneldisplay cover the grating at least once, wherein the center point isgenerated based on a predetermined or, alternatively, desired randomdistribution and a size of the grating is determined in advance, andcalculating G_(i) corresponding to a gap between the screen of theflat-panel display and a raster of the grating using a predetermined or,alternatively, desired method with respect to the respective gratingR_(ij), wherein G_(ij) is a constant, i is a value of 1 through N_(s),N_(s) denotes a total number of gratings, and G(x, y) corresponding to agap between the calculated raster and the flat-panel display satisfiesthe following equation: G(x, y)=(1/N_(a))*Σ_(i=1) ^(N) ^(s)[a(x,y,i)*G_(i)] where if [x, y]∈R_(i), a(x,y,i) is 1, and if not [x,y]∈R_(i), a(x,y,i) is zero and N_(a)=Σ_(i=1) ^(N) ^(s) a(x,y,i), and thepredetermined or, alternatively, desired method may include acquiring atleast two image rows by performing sampling in a stripe imagecorresponding to the grating and the rectified image at preset or,alternatively, desired sampling intervals, acquiring a local periodfunction T_(r)(x; y_(r)) of a signal corresponding to an r^(th) imagerow acquired through the sampling, wherein, in T_(r)(x; y_(r)), xdenotes a horizontal coordinate on the screen of the flat-panel display,y_(r) denotes a vertical coordinate of the r^(th) image row on thescreen of the flat-panel display, r is a value of 1 through N, and Ndenotes a total number of image rows acquired through the sampling,calculating G_(r)(x; y_(r)) corresponding to a gap between theflat-panel display and a raster corresponding to the r^(th) image row,G_(r)(x; y_(r)) satisfying the following equations: G_(r)(x;y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotes adistance between the screen of the flat-panel display and the capturingdevice, P_(x) denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and calculating G(x)=Σ_(r=1) ^(N)G_(r)/Nand acquiring G_(ij) by calculating an x-directional average value usingG(x).

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the calculating of the rasterparameter based on the captured stripe image may include acquiring atleast two sampling points by performing sampling on the screen of theflat-panel display and generating a grating in a predetermined or,alternatively, desired size based on each of the sampling points as acenter point, calculating G_(pk) corresponding to a gap between thescreen of the flat-panel display and a raster of the grating using apredetermined or, alternatively, desired method for each grating R_(pk),wherein G_(pk) is a constant, p is a value of 1 through N_(p), k is avalue of 1 through N_(k), N_(p) denotes a number of rows in the grating,and N_(k) denotes a number of columns in the grating, and acquiring G(x,y) corresponding to a gap between the raster and the flat-panel displaythrough an interpolation of a three-element set{[x_(pk),y_(pk),G_(pk)]}, where [x_(pk), y_(pk)] denotes coordinates ofa center point of the grating R_(pk) on the screen of the flat-paneldisplay, and G_(pk) denotes a gap between a raster in the grating R_(pk)and the screen of the flat-panel display, and the predetermined or,alternatively, desired method may include acquiring at least two imagerows by performing sampling in a stripe image corresponding to thegrating and the rectified image at preset or, alternatively, desiredsampling intervals, acquiring a local period function T_(r)(x; y_(r)) ofa signal corresponding to an r^(th) image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, y_(r) denotes a verticalcoordinate of the r^(th) image row on the screen of the flat-paneldisplay, r is a value of 1 through N, and N denotes a total number ofimage rows acquired through the sampling, calculating G_(r)(x; y_(r))corresponding to a gap between the flat-panel display and a rastercorresponding to the r^(th) image row, G_(r)(x; y_(r)) satisfying thefollowing equations: G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r))))where D_(cam) denotes a distance between the screen of the flat-paneldisplay and the capturing device, P_(x) denotes a horizontal rasterinterval of the raster, and Tsr(x; y_(r)) is a period change functionfor which the capturing device performs sampling by penetrating theraster relative to the screen of the flat-panel display; and Tsr(x;y_(r))=T_(c)(y_(r))*T_(r)(x; y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) whereT_(c)(y_(r)) denotes a period of the r^(th) image row, and calculatingG(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring G_(pk) by calculatingan x-directional average value using G(x).

A method of acquiring the local period function of the signalcorresponding to the r^(th) image row may include calculating a numberof pixels Num corresponding to a distance between neighboring peaksbased on peaks, each acquired from the signal corresponding to the imagerow, wherein the distance between the neighboring peaks isNum*Ws/PixNum, Ws denotes a width of a raster area corresponding to asampled stripe image, and PixNum denotes a number of pixels in the imagerow, and acquiring a local period function T_(r)(x; y_(r)) of the signalcorresponding to the image row by performing fitting on the distancebetween the neighboring peaks.

A method of correcting the stereoscopic image displayed on theflat-panel display based on the calculated raster parameter may includeacquiring a light beam model of the naked-eye 3D display based on thecalculated raster parameter, and controlling the naked-eye 3D display togenerate a stereoscopic image using the light beam model.

Other example embodiments relate to an apparatus for correcting an imageerror in a naked-eye 3D display.

In some example embodiments, the apparatus may include a displaycontroller configured to control a flat-panel display displaying astripe image, a raster parameter calculator configured to calculate araster parameter of the naked-eye 3D display based on a captured stripeimage, the captured stripe image being displayed after the stripe imagedisplayed on the flat-panel display passes through a raster provided ona surface of the flat-panel display, and a stereoscopic image correctorconfigured to correct a stereoscopic image displayed on the naked-eye 3Ddisplay based on the calculated raster parameter, wherein the naked-eye3D display includes the flat-panel display and the raster.

An image of each row in the stripe image displayed on the flat-paneldisplay may have a periodic signal of an equal wavelength, and theperiodic signal may have a change in brightness in a wavelength of eachperiod.

S1(x, y) corresponding to the stripe image may satisfy the followingequations: S1(x,y)=A1*0.5[sin(W_(c)*(x−P1))+1] where x denotes ahorizontal coordinate of a pixel of the stripe image on a screen of theflat-panel display, y denotes a vertical coordinate of the pixel, A1denotes an amplitude of the stripe image, and P1 denotes an error in thestripe image; W_(c)=2π/T_(c), T_(c)=(T_(o)*T_(b))/(T_(o)+T_(b)) whereT_(b) denotes a sampling period of the raster on the screen of theflat-panel screen; T_(min)<T_(o)<M*T_(min) where M is a predeterminedor, alternatively, desired constant; andT_(min)=2*D_(v)*tan(A_(m)/2)*P_(m)/R_(m) where D_(v) denotes a viewingdistance of the naked-eye 3D distance, A_(m) denotes a horizontal angleof a capturing device used for capturing, P_(m) denotes a number ofpixels in a gap between stripes to be extracted during an imageprocessing, and R_(m) denotes a horizontal pixel resolution of thecapturing device.

The apparatus may further include an image rectifier configured torectify an image including the captured stripe image before the rasterparameter calculator calculates the raster parameter based on thecaptured stripe image, and the raster parameter calculator may be usedby the image rectifier for a raster parameter of the naked-eye 3Ddisplay based on a stripe image of the rectified image.

The rectified image and an unrectified image may satisfy the followingequation: u*[x_(s),y_(s),l]^(T)=H*[x_(i),y_(i),l]^(T) where u denotes astandardization factor, P_(i)=[x_(i),y_(i)] is coordinates of apredetermined or, alternatively, desired pixel of the unrectified image,P_(s)=[x_(s),y_(s)] is coordinates of a pixel of the rectified imagecorresponding to the predetermined or, alternatively, desired pixel ofthe unrectified image, and H denotes a homographic transformationmatrix.

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the raster parameter calculatormay include an image row sampler configured to acquire at least twoimage rows by performing sampling in the stripe image of the rectifiedimage at preset or, alternatively, desired sampling intervals, a localperiod function acquirer configured to acquire a local period functionT_(r)(x; y_(r)) of a signal corresponding to an r^(th) image rowacquired through the sampling, wherein, in T_(r)(x; y_(r)), x denotes ahorizontal coordinate on the screen of the flat-panel display, y_(r)denotes a vertical coordinate of the r^(th) image row on the screen ofthe flat-panel display, r is a value of 1 through N, and N denotes atotal number of image rows acquired through the sampling, a gapcalculator configured to calculate G_(r)(x; y_(r)) corresponding to agap between the screen of the flat-panel display and a rastercorresponding to the r^(th) image row, G_(r)(x; y_(r)) satisfying thefollowing equations: G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r))))where D_(cam) denotes a distance between the screen of the flat-paneldisplay and the capturing device, P_(x) denotes a horizontal rasterinterval, and Tsr(x; y_(r)) is a period change function for which thecapturing device perform sampling by penetrating the raster relative tothe screen of the flat-panel display; and Tsr(x;y_(r))=T_(c)(y_(r))*T_(r)(x; y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) whereT_(r) (y_(r)) denotes a period of the r^(th) image row, and a fittingunit configured to perform fitting based on a three-element set {[x_(c),y_(r), G_(r)(x; y_(r))]} and acquire a gap G(x, y) between the rasterand the flat-panel display, wherein, in {[x_(c), y_(r), G_(r)(x;y_(r))]}, [x_(c),y_(r)] denotes coordinates of a pixel on the screen ofthe flat-panel display and G_(r)(x; y_(r)) denotes a gap between thescreen of the flat-panel display and the raster corresponding to thepixel.

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the raster parameter calculatormay include a divider configured to divide the screen of the flat-paneldisplay into at least two neighboring gratings {R_(ij)} having the samesize, wherein, in R_(ij), i is a value of 1 through N_(r), j is a valueof 1 through N_(c), N_(r) denotes a number of rows of a grating acquiredthrough a division, and N_(c) denotes a number of columns of thegrating, a grating gap calculator configured to calculate a gap G_(ij)between the screen of the flat-panel display and a raster of the gratingusing a predetermined or, alternatively, desired method with respect tothe respective grating R_(ij), G_(ij) being a constant, and an overallgap calculator configured to calculate a gap G(x, y) between theflat-panel display and the raster of the naked-eye 3D display, G(x, y)being equal to G_(ij) if [x, y]∈R_(ij), and the predetermined or,alternatively, desired method may include acquiring at least two imagerows by sampling a stripe image corresponding to the gratings and therectified image at preset or, alternatively, desired sampling intervals,acquiring a local period function T_(r)(x; y_(r)) of a signalcorresponding to an r^(th) image row acquired through the sampling,wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinate on thescreen of the flat-panel display, y_(r) denotes a vertical coordinate ofthe r^(th) image row on the screen of the flat-panel display, r is avalue of 1 through N, and N denotes a total number of image rowsacquired through the sampling, calculating G_(r)(x; y_(r)) correspondingto a distance between the flat-panel display and a raster correspondingto the r^(th) image row, G_(r)(x; y_(r)) satisfying the followingequations: G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) whereD_(cam) denotes a distance between the screen of the flat-panel displayand the capturing device, P_(x) denotes a horizontal raster interval,and Tsr(x; y_(r)) is a period change function for which the capturingdevice performs sampling by penetrating the raster relative to thescreen of the flat-panel display; and Tsr(x;y_(r))=T_(c)(y_(r))*T_(r)(x; y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) whereT_(c)(y_(r)) denotes a period of the r^(th) image row, and calculatingG(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring G_(ij) by calculatingan x-directional average value using G(x).

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the raster parameter calculatormay include a grating generator configured to generate a gratingcorresponding to a grating center point gradually and iteratively suchthat all regions on the screen of the flat-panel display cover thegrating at least once, wherein the center point is generated based on apredetermined or, alternatively, desired random distribution and a sizeof the grating is determined in advance, a grating gap calculatorconfigured to calculate G_(i) corresponding to a gap between the screenof the flat-panel display and a raster of the grating using apredetermined or, alternatively, desired method with respect to therespective grating R_(i), wherein G_(i) is a constant, i is a value of 1through N_(s), and N_(s) denotes a total number of grating, and anoverall gap calculator configured to calculate G(x, y) corresponding toa gap between the calculated raster and the flat-panel display satisfiesthe following equation: G(x, y)=(1/N_(a))*Σ_(i=1) ^(N) ^(s)[a(x,y,i)*G_(i)] where if [x, y]∈R_(i), a(x,y,i) is 1, and if not [x,y]∈R_(i), a(x,y,i) is zero and N_(a)=Σ_(i=1) ^(N) ^(s) a(x,y,i), and thepredetermined or, alternatively, desired method may include acquiring atleast two image rows by performing sampling in a stripe imagecorresponding to the grating and the rectified image at preset or,alternatively, desired sampling intervals, acquiring a local periodfunction T_(r)(x; y_(r)) of a signal corresponding to an r^(th) imagerow acquired through the sampling, wherein, in T_(r)(x; y_(r)), xdenotes a horizontal coordinate on the screen of the flat-panel display,y_(r) denotes a vertical coordinate of the r^(th) image row on thescreen of the flat-panel display, r is a value of 1 through N, and Ndenotes a total number of image rows acquired through the sampling,calculating G_(r)(x; y_(r)) corresponding to a gap between theflat-panel display and a raster corresponding to the r^(th) image row,G_(r)(x; y_(r)) satisfying the following equations: G_(r)(x;y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotes adistance between the screen of the flat-panel display and the capturingdevice, P_(x) denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperform sampling by penetrating the raster relative to the screen of theflat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and calculating G(x)=Σ_(r=1)^(N)G_(r)(x; y_(r))/N and acquiring G_(i) by calculating anx-directional average value using G(x).

When the raster parameter corresponds to a gap between the raster andthe screen of the flat-panel display, the raster parameter calculatormay include a grating generator configured to acquire at least twosampling points by performing sampling on the screen of the flat-paneldisplay and generate a grating in a predetermined or, alternatively,desired size based on each of the sampling points as a center point, agrating gap calculator configured to calculate G_(pk) corresponding to agap between the screen of the flat-panel display and a raster of thegrating using a predetermined or, alternatively, desired method withrespect to each grating R_(pk), wherein G_(pk) is a constant, p is avalue of 1 through N_(p), k is a value of 1 through N_(k), N_(p) denotesa number of rows in the grating, and N_(k) denotes a number of columnsin the grating, and an overall gap calculator configured to acquire G(x,y) corresponding to a gap between the raster and the flat-panel displaythrough an interpolation of a three-element set{[x_(pk),y_(pk),G_(pk)]}, where [x_(pk), y_(pk)] denotes coordinates ofa center point of the grating R_(pk) on the screen of the flat-paneldisplay, and G_(pk) denotes a gap between a raster in the grating R_(pk)and the screen of the flat-panel display, and the predetermined or,alternatively, desired method may include acquiring at least two imagerows by performing sampling in a stripe image corresponding to thegrating and the rectified image at preset or, alternatively, desiredsampling intervals, acquiring a local period function T_(r)(x; y_(r)) ofa signal corresponding to an r^(th) image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, y_(r) denotes a verticalcoordinate of the r^(th) image row on the screen of the flat-paneldisplay, r is a value of 1 through N, and N denotes a total number ofimage rows acquired through the sampling, calculating G_(r)(x; y_(r))corresponding to a gap between the flat-panel display and a rastercorresponding to the r^(th) image row, G_(r)(x; y_(r)) satisfying thefollowing equations: G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r))))where D_(cam) denotes a distance between the screen of the flat-paneldisplay and the capturing device, P_(x) denotes a horizontal rasterinterval of the raster, and Tsr(x; y_(r)) is a period change functionfor which the capturing device performs sampling by penetrating theraster relative to the screen of the flat-panel display; and Tsr(x;y_(r))=T_(c)(y_(r))*T_(r)(x; y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) whereT_(c)(y_(r)) denotes a period of the r^(th) image row, and calculatingG(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring G_(pk) by calculatingan x-directional average value using G(x).

The apparatus for correcting an image error in the naked-eye 3D displayis configured to calculate a number of pixels Num corresponding to adistance between neighboring peaks based on peaks, each acquired fromthe signal corresponding to the image row, wherein the distance betweenthe neighboring peaks is Num*Ws/PixNum, Ws denotes a width of a rasterarea corresponding to a sampled stripe image, and PixNum denotes anumber of pixels in the image row, and acquire a local period functionT_(r)(x; y_(r)) of the signal corresponding to the image row byperforming fitting on the distance between the neighboring peaks.

The stereoscopic image correcting module may include a light beam modelacquirer configured to acquire a light beam model of the naked-eye 3Ddisplay based on the calculated raster parameter, and a stereoscopicimage generation controller configured to control the naked-eye 3Ddisplay to generate a stereoscopic image using the light beam model.

The aforementioned contents may be applicable to a naked 3D displayincluding a flat-panel display and a raster. It is possible to correct astereoscopic image display on the naked-eye 3D display by controlling astripe image displayed on the flat-panel display, capturing a stripeimage after the stripe image displayed on the flat-panel displaypenetrates the raster, calculating a raster parameter of the naked-eye3D display based on the captured stripe image, and adjusting a method ofan image generated by the flat-panel display based on the calculatedraster parameter. Through this, a quality of the stereoscopic imagedisplayed on the naked-eye 3D display and a satisfaction of a userviewing the stereoscopic image may be enhanced.

Additional aspects of example embodiments will be set forth in part inthe description which follows and, in part, will be apparent from thedescription, or may be learned by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of example embodiments, takenin conjunction with the accompanying drawings of which:

FIG. 1 illustrates an example of a naked-eye three-dimensional (3D)display according to at least one example embodiment;

FIGS. 2A through 2C illustrate examples of a naked 3D display having anerror in a gap between a raster and a flat-panel display in comparisonto the gap being an ideal value according to at least one exampleembodiment;

FIG. 3 illustrates an example of a method of correcting an image errorin a naked-eye 3D display according to at least one example embodiment;

FIG. 4 illustrates an example of a stripe image displayed on aflat-panel display according to at least one example embodiment;

FIG. 5 illustrates an example of a relative position between a naked-eye3D display and a capturing device according to at least one exampleembodiment;

FIG. 6 illustrates an example of a rectified image in comparison to anunrectified image according to at least one example embodiment;

FIG. 7 illustrates an example of a signal peak extracted from an imagerow according to at least one example embodiment;

FIG. 8 illustrates an example of a local period function of an image rowacquired by performing fitting using a local signal period valueaccording to at least one example embodiment;

FIG. 9 illustrates an example of a positional relationship between acoordinate system of a capturing device and a coordinate system of ascreen of a flat-panel display according to at least one exampleembodiment;

FIG. 10 illustrates an example of a gap between a screen of a flat-paneldisplay and a raster in a naked-eye 3D display, the gap which isacquired through a fitting based on a three-element set{[x_(c),y_(r),G_(r)(x_(c); y_(r))]} according to at least one exampleembodiment;

FIG. 11 illustrates an example of dividing a screen of a flat-paneldisplay into gratings according to at least one example embodiment;

FIG. 12 illustrates another example of dividing a screen of a flat-paneldisplay into gratings according to at least one example embodiment;

FIG. 13 illustrates still another example of dividing a screen of aflat-panel display into gratings according to at least one exampleembodiment;

FIG. 14 illustrates an example of a screen direction vertical to araster axis in a process of dividing a screen of a flat-panel displayinto gratings according to at least one example embodiment;

FIG. 15 illustrates an example of an apparatus of correcting an imageerror in a naked-eye 3D display according to at least one exampleembodiment;

FIG. 16 illustrates an example of a raster parameter calculator includedin an apparatus for correcting an image error of a naked-eye 3D displayaccording to at least one example embodiment;

FIG. 17 illustrates another example of a raster parameter calculatorincluded in an apparatus for correcting an image error of a naked-eye 3Ddisplay according to at least one example embodiment;

FIG. 18 illustrates still another example of a raster parametercalculator included in an apparatus for correcting an image error of anaked-eye 3D display according to at least one example embodiment; and

FIG. 19 illustrates an example of a stereoscopic image correctorincluded in an apparatus for correcting an image error in a naked-eye 3Ddisplay according to at least one example embodiment.

DETAILED DESCRIPTION

Hereinafter, some example embodiments will be described in detail withreference to the accompanying drawings. Regarding the reference numeralsassigned to the elements in the drawings, it should be noted that thesame elements will be designated by the same reference numerals,wherever possible, even though they are shown in different drawings.Also, in the description of embodiments, detailed description ofwell-known related structures or functions will be omitted when it isdeemed that such description will cause ambiguous interpretation of thepresent disclosure.

It should be understood, however, that there is no intent to limit thisdisclosure to the particular example embodiments disclosed. On thecontrary, example embodiments are to cover all modifications,equivalents, and alternatives falling within the scope of the exampleembodiments. Like numbers refer to like elements throughout thedescription of the figures.

In addition, terms such as first, second, A, B, (a), (b), and the likemay be used herein to describe components. Each of these terminologiesis not used to define an essence, order or sequence of a correspondingcomponent but used merely to distinguish the corresponding componentfrom other component(s). It should be noted that if it is described inthe specification that one component is “connected”, “coupled”, or“joined” to another component, a third component may be “connected”,“coupled”, and “joined” between the first and second components,although the first component may be directly connected, coupled orjoined to the second component.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the,” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises,” “comprising,”“includes,” and/or “including,” when used herein, specify the presenceof stated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedsubstantially concurrently or may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

Various example embodiments will now be described more fully withreference to the accompanying drawings in which some example embodimentsare shown. In the drawings, the thicknesses of layers and regions areexaggerated for clarity.

Hereinafter, to solve an issue that an error in a three-dimensional (3D)image displayed on a naked-eye 3D display affects a view quality,descriptions of a method of correcting an image error of a naked-eye 3Ddisplay and an apparatus for correcting an image error of a naked-eye 3Ddisplay using the method will be provided with reference to thefollowing examples.

Referring to FIG. 1, a raster may disperse light to represent differentsub-pixel sets of a flat-panel display at different angles and positionsin a region of view. Based on a type of display technology, the rastermay be implemented as, for example, a slot raster, a liquid crystaldisplay (LCD), and a lens array.

FIG. 2A illustrates an example of an ideal arrangement of a raster and aflat-panel display. FIGS. 2B and 2C illustrate examples of a rastererror that may occur in practice. A raster inclination error occurs inan example of FIG. 2B, and a non-linear raster transformation erroroccurs in an example of FIG. 2C.

Referring to FIG. 3, a method of correcting an image error of anaked-eye 3D display includes the following operations.

In operation 102, a display controller may control a stripe imagedisplayed on a flat-panel display. For example the display controllermay control a display to display the stripe image such that, in thedisplayed stripe image, image rows may each be a periodic signal havingthe same wavelength and the periodic signal may have a change inbrightness in a wavelength in each period. In operation 104, an imagerectifier may calculate a raster parameter of the naked-eye 3D displaybased on a captured stripe image and the captured stripe image may bedisplayed after the stripe image displayed on the flat-panel displaypenetrates a raster. In operation 106, a stereoscopic image correctormay correct a stereoscopic image displayed on the naked-eye 3D displaybased on the calculated raster parameter. According to at least someexample embodiments, the displayed stripe image may be an image that isdisplayed through a raster, and the image displayed through the rastermay be captured as the captured image.

In FIG. 4, a brightness-periodicity changing stripe image displayed onthe flat-panel image may also be referred to as a calibration stripeimage. In the calibration stripe image, image rows may each be indicatedby a periodic signal having the same periodicity and the periodic signalmay have a change in brightness of a wavelength in each period. Theperiodic signal may be indicated by, for example, a period T_(c), and aphase position H. For example, the periodic signal may be, but notlimited to, a sine signal, a clock signal, or other type of periodicalsignal having a unit period.

After penetration of a raster of the naked-eye 3D display, a stripeimage having different frequency and orientation may be generated basedon the calibration stripe image. The generated stripe image may also bereferred to as, for example, an observation stripe image. An ideallyreadily used observation stripe image may allow a user to use a generalcapturing device for capturing, capture a picture of at least oneobservation stripe image in a normal viewing distance, and acquire araster parameter of the naked-eye 3D display in operation 104 as below.To allow the observation stripe image to achieve such characteristic,the calibration stripe image may be generated using the followingmethod.

Referring to FIG. 5, with respect to a naked-eye 3D display using onecolumn-type raster, it is assumed that a raster gap (pitch of barrier)is P_(b), an installation angle (slanted angle) is A_(s), a gap betweena raster and a flat-panel display or a prism lens array thickness isG_(b), a designed viewing distance of the naked-eye 3D display is D_(v)based on a design value. A sampling period of the raster on theflat-panel display in the designed viewing distance D_(v) may be T_(b)and, for example, T_(b)=P_(b)*(D_(v)+G_(b))/(cos A_(s)*D_(v)).

The capturing device, for example a camera, used by the user may capturethe observation stripe image displayed on the naked-eye 3D display. Thecamera may be, for example, a digital camera. The digital camera may be,for example, a camera having one or more complementary metal oxidesemiconductor (CMOS) image sensors and/or one or more charge-coupleddevice (CCD) image sensors. In this example, when it is assumed that ahorizontal angle of the capturing device is A_(m), a vertical pixelresolution of the capturing device is R_(m), a number of pixels of astripe gap to be accurately extracted in during an image processing isP_(m), and a width of the naked-eye 3D display is W_(d), a period of astripe image observed on a screen of the flat-panel display screen mayneed to be greater than T_(min) to perform extraction, and T_(min) maybe calculated according to Equation 1.T _(min)=2*D _(v)*tan(A _(m)/2)*P _(m) /R _(m)  [Equation 1]

In practice, to compute a local change, a period T₀ of the stripe imageobserved on the screen of the flap-panel display may be set to be withinan appropriate range, for example, T_(min)<T₀<M*T_(min). Here, M may bea predetermined or, alternatively, desired constant, for example, M=5.

As such, a period T_(c) of the calibration stripe image may becontrolled using Equation 2.T _(c)=(T ₀ *T _(b))/(T _(o) +T _(b))  [Equation 2]

S1(x, y) corresponding to the calibration stripe image may be generatedusing Equation 3.S1(x,y)=A1*0.5*[sin(W _(c)*(x−P1))+1]  [Equation 3]

In Equation 3, x and y denote respectively a horizontal coordinate and avertical coordinate of a pixel of the calibration stripe image on thescreen of the flat-panel display. A1 denotes an amplitude of thecalibration stripe image and, for example, A1 may be set to be “255” foran 8-bit brightness image. W_(c) denotes a frequency of the calibrationstripe image and, for example, W_(c)=2π/T_(c). P1 denote a total errorin the calibration stripe image and may be set to be zero.

As shown in Equation 3, S1(x) corresponding to a brightness value of apixel at a position x of one image row may satisfy“S1(x)=A1*0.5*[sin(W_(c)*(x−P1))+1]”. “S1(x)=0” may be a brightnessvalue obtained when a brightness of the pixel is the lowest. “S1(x)=A1”may be a brightness value obtained when the brightness of the pixel isthe highest. When x changes in one period, a value applied to S1(x) maychange in a range between 0 and A1. Concisely, although a wavelength ofan image row has a brightness change in one period, the image row may bea periodic signal. Since the periodic signal has the same wavelength ineach period, the image row may have the same brightness change of awavelength in each period.

The image rectifier may calculate a raster parameter of the naked-eye 3Ddisplay based on a captured stripe image in operation 104. The capturedstripe image may be displayed after the stripe image displayed on theflat-panel display, for example, the calibration stripe image penetratesthe raster. For example, operation 104 may include two processes asbelow.

Process 1

An image including a captured stripe image may be rectified. Forexample, a capturing device may capture an image with respect to theobservation stripe image displayed on the naked-eye 3D display. Thecaptured image may be rectified and property information on an accurateraster may be extracted from the rectified image. In this example,coordinate systems of the screen of the flat-panel display and therectified image may be aligned through a rectification.

Referring to FIG. 6, an image of a capturing device may be inaccuratelycontrolled. Thus, a difference in image conversion between the screen ofthe flat-panel display of a captured image and an actual screen mayoccur. The difference in image conversion may be determined based on,for example, a positional state of the capturing device and a lensparameter of the capturing device.

In response to the rectifying of the image captured by the capturingdevice through an image conversion, the rectified image and a coordinatesystem of the screen of the flat-panel display may be aligned. Theunrectified image may be shown in a left portion of FIG. 6, and therectified image may be shown in a right portion of FIG. 6. For example,P_(i)=[x_(i), y_(i)] may be coordinates of the pixel in the unrectifiedimage and P_(s)=[x_(s),y_(s)] may be coordinates of the correspondingpixel in the rectified image.

In this example, a predetermined or, alternatively, desired pixel of theunrectified image and a corresponding pixel of the rectified image maysatisfy Equation 4.u*[x _(s) ,y _(s),1]^(T) =H*[x _(i) ,y _(i),1]^(T)  [Equation 4]

In Equation 4, u denotes a constant representing a standardizationfactor, H denotes a homographic matrix. The homographic matrix H may beacquired through an extraction of a feature point using a least squaremethod.

For example, four corner points of the screen of the flat-panel displaymay be set to be feature points. As illustrated in FIG. 6, four cornerpoints of the unrectified image may be A_(i), B_(i), C_(i), and D_(i),and four corner points of the rectified image may be A_(s), B_(s),C_(s), and D_(s). Coordinates of the four corner points in each of theunrectified image and the rectified image may be calculated based on acorner point extraction method. Coordinates of A_(i) and A_(s),coordinates of B_(i) and B_(s), coordinates of C_(i) and C_(s), andcoordinates of D_(i) and D_(s) may be substituted to Equation 4 so as toacquire the homographic matrix H using the least square method.

After pixel coordinates of each pixel in the rectified image areacquired, the pixel coordinates may be converted into positionalcoordinates on the screen of the flat-panel display based on a length ofa side of a tetragonal area corresponding to the pixel on the screen ofthe flat-panel display. For example, the length of the side of thetetragonal area may be 1 millimeter (mm), pixel coordinates of a pixelof a zeroth column and a zeroth row are [0, 0], and the pixelcoordinates may be present outside an image in practice. In thisexample, when an origin of a coordinate system on the screen of theflat-panel display is set to be the pixel [0, 0], pixel coordinates[x_(s), y_(s)] of a pixel of the rectified image may be converted intopositional coordinates [l*x_(s),l*y_(s)] on the screen of the flat-paneldisplay.

Process 2

The raster parameter of the naked-eye 3D display may be calculated basedon the stripe image in the rectified image. For example, a parameterassociated with a gap between the raster and the screen of theflat-panel display, a parameter associated with a parallel translationof the raster relative to the screen of the flat-panel display, and aparameter associated with a rotation of the raster relative to thescreen of the flat-panel display may be calculated.

A method of calculating a raster parameter corresponding to a parameterassociated with a gap between the raster and the screen of theflat-panel display is described with reference to the foregoing example.Hereinafter, two methods of calculating the parameter associated with agap between the raster and the screen of the flat-panel display will bedescribed.

Method 1

A stripe image in a rectified image may be extracted and a sampling maybe performed in the extracted stripe image at preset or, alternatively,desired sampling intervals. Through this, a group of image rows may beacquired. In this example, a region other than that of the screen of theflat-panel display may also be captured in practice. The image rows maybe acquired through a sampling based on an equal-spacing scheme.

A low-frequency pass filter may be used to filter the image rowsacquired through the sampling and remove noise from the image rows. Thefollowing operations may be performed on an image row acquired throughthe sampling.

A local period function acquirer may acquire peaks corresponding to theimage row and calculate a number of pixels Num in a gap betweenneighboring peaks.

The local period function acquirer may calculate a distance between theneighboring peaks based on the number of pixels Num.

The local period function acquirer may acquire a local period functionof a signal corresponding to the image row by performing fitting on thedistance between the neighboring peaks.

Referring to FIG. 7, a size of a neighboring pixel for each pixel on theimage row may be calculated. Through this, a local maximum value of theimage row may be extracted and the extracted local maximum value may bestored as a signal peak value. When the gap between the screen of theflat-panel display and the raster of the naked-eye 3D display is equalto an ideal value, the image row may be an ideal periodic signal,distances separating signal peaks may be equalized, and the distancesmay be the same as signal periods. When the raster includes an error, adifference between signal peaks may occur. In this example, a distancebetween neighboring peaks may correspond to a local period of a signal.An image distance between neighboring peaks, for example, the number ofpixels Num in the gap between the neighboring peaks may be calculatedand the image distance may be converted into a distance. Through this,the local period function corresponding to the image row may becalculated and acquired.

The distance between the neighboring peaks may be calculated accordingto Equation 5.PeakDist=Num*Ws/PixNum  [Equation 5]

In Equation 5, Ws denotes a width of a raster area corresponding to theextracted stripe image and PixNum denotes a number of pixels of an imagerow.

Referring to FIG. 8, a local period function T_(r)(x; y_(r)) of a signalcorresponding to the image row may be acquired through a fitting of alocal period value, for example, the distance between the neighboringpeaks. x represents a horizontal coordinate on the screen of theflat-panel display, y_(r) represents a vertical coordinate of an r^(th)image row on the screen of the flat-panel display, r is a value of 1through N, and N denotes a total number of image rows acquired throughthe sampling.

A gap G_(r)(x; y_(r)) between the screen of the flat-panel display and araster corresponding to the image row may be calculated according toEquation 6.G _(r)(x;y _(r))=D _(cam)*(1−P _(x) /Tsr(x;y _(r))))  [Equation 6]

In Equation 6, D_(cam) denotes a distance between the capturing deviceused for capturing and the screen of the flat-panel display and P_(x)denotes a horizontal raster gap.

When it is assumed that a prism raster is positioned at an angle A_(b)and the angle A_(b) is an included angle between a vertical line and anaxis line of a prism, P_(x)=P_(b)/cos(A_(b)), P_(b) may be a verticaldistance between two prism axis lines neighboring the prism raster,Tsr(x; y_(r)) may be a period change function for which the capturingdevice performs sampling through a penetration of the raster relative tothe screen of the flat-panel display, and Tsr(x; y_(r))=T_(r)(y_(r))*T_(r)(x; y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))), T_(c)(y_(r))being a period of the r^(th) image row.

D_(cam) may be acquired using one camera pose calculator. For example,using the camera pose calculator, the capturing device may calculate anattitude R_(c) and a position T_(c) with respect to a coordinate systemon the screen of the flat-panel display and acquire D_(cam).

When it is assumed that the capturing device is able to represent thefigure and the position on the screen of the flat-panel display in formsof a rotation matrix R_(c) and a parallel translation vector T_(c), arelationship between a known 3D space point M_(i)=[X_(i),Y_(i), Z_(i)]and a corresponding image point P_(i)=[x_(i),y_(i)] may satisfy Equation7 with reference to FIG. 9.u*[x _(i) ,y _(i),1]^(T) =K _(c)*[R _(c) T _(c)]*[X _(i) ,Y _(i) ,Z_(i),1]^(T)  [Equation 7]

In Equation 7, K_(c) denotes a known parameter in the capturing device.

When the 3D space point M_(i)=[X_(i), Y_(i), Z_(i)] is on the screen ofthe flat-panel display, and when Z_(i)=0, Equation 8 used forsimplification may be acquired as shown below.u*[x _(i) ,y _(i),1]^(T) =K _(c)*[r ₁ r ₂ T _(x)]*[X _(i) ,Y_(i),1]^(T)  [Equation 8]

R_(c)=[r₁r₂r₃], r₁, r₂ may be a first column and a second column of therotation matrix R_(c), and K_(c) may be a 3×3 matrix. Thus,[r₁r₂T_(c)]=u*K_(c) ⁻¹*H.

r₃ and T_(c) may be acquired based on a unit orthogonality of therotation matrix the capturing device may further acquire the positionT_(c) and the attitude R_(c) of the coordinate system on the screen ofthe flat-panel display.

Also, in an actual operation, an image row neighboring the r^(th) imagerow may be used in a process of calculating G_(r)(x; y_(r)) to reduce anadverse effect of noise.

When operations S202 through S208 are performed all of the image rowsacquired through the sampling, G₁(x; y₁), G₂(x; y₂), . . . , G_(r)(x;y_(r)), G_(N)(x; y_(N)) corresponding to gap values between theflat-panel display and a group of rasters may be acquired with referenceto FIG. 10. Through this, one three-element set{[x_(c),y_(r),G_(r)(x_(c); y_(r))]} may be acquired. In thethree-element set, all predetermined or, alternatively, desired elements[x_(c),y_(r),G_(r)(x_(c); y_(r))] may be one three-element. In[x_(c),y_(r),G_(r)(x_(c); y_(r))], [x_(c),y_(r)] denotes coordinates ofone pixel on the screen of the flat-panel display, and G_(r)(x_(c);y_(r)) denotes a gap value of a gap between the screen of the flat-paneldisplay and a raster corresponding to the pixel. Also, all coordinatescorresponding to [x_(c), y_(r)] may be distributed on the screen of theflat-panel display.

Through a fitting performed using the three-element set{[x_(c),y_(r),G_(r)(x_(c); y_(r))]}, a gap function G(x, y) between thescreen of the flat-panel display and the raster may be acquired. In G(x,y), (x, y) represent coordinates of a position of a predetermined or,alternatively, desired point on the screen of the flat-panel display.

Method 2

In method 2, the screen of the flat-panel display may be divided into aplurality of local regions. In this example, under an assumption that agap value between the screen of the flat-panel display and a rastercorresponding to each of the local regions is a constant, the gap valuemay be calculated for each of the local regions. Based on the gap value,a gap between the screen of the flat-panel display and a rastercorresponding to the entire screen of the flat-panel display may becalculated.

Based on different schemes of dividing the entire screen of theflat-panel display into a plurality of local regions, the gap betweenthe screen of the flat-panel display and the raster corresponding to theentire screen of the flat-panel display may be calculated using thefollowing schemes.

Scheme 1

Referring to FIG. 11, the screen of the flat-panel display may bedivided into a plurality of neighboring gratings having the same size.In R_(ij), i may be a value of 1 through N_(r) and j may be a value of 1through N_(c). A gap between the screen of the flat-panel display andthe raster corresponding to each of the gratings may be a value of aconstant.

An N^(th) image row may be acquired by performing sampling in a stripeimage of a grating R_(ij) at preset or, alternatively, desired samplingintervals for each of the gratings {R_(ij)}. Operations S202 throughS208 may be performed on each image row acquired through the sampling toacquire a gap G_(r)(x; y_(r)) between the screen of the flat-paneldisplay and a raster corresponding to each image row. When operationsS202 through S208 are performed on the N^(th) image row acquired throughthe sampling, gap values: G₁(x; y₁), G₂ (x; y₂), . . . , G_(r)(x;y_(r)), . . . , G_(N)(x; y_(N)) between the flat-panel display and agroup of rasters may be acquired. Also, G(x)=Σ_(r=1) ^(N)G_(r)(x;y_(r))/N may be calculated and an x-directional average value may becalculated using G(x). Through this, a gap G_(ij) between the screen ofthe flat-panel display and the raster corresponding to the gratingR_(ij) may be acquired.

The gap G(x, y) between the screen of the flat-panel display and theraster corresponding to, the entire screen of the flat-panel display maysatisfy Equation 9.If [x,y]∈R _(ij) ,G(x,y)=G _(ij)  [Equation 9]

In G(x, y), (x, y) may be coordinates of a position of a predeterminedor, alternatively, desired point on the screen of the flat-paneldisplay.

Scheme 2

Referring to FIG. 12, generating a grating corresponding to a gratingcenter point gradually through an iteration such that all regions on thescreen of the flat-panel display covers the grating at least once,wherein the center point is generated based on a predetermined or,alternatively, desired random distribution and a size of the grating isdetermined in advance

A center point [x_(i), y_(i)] of a plurality of gratings {R_(i)} may begenerated based on a predetermined or, alternatively, desired randomdistribution, for example, an equalized distribution and generate agrating corresponding thereto. Here, i may be a value of 1 throughN_(i). In this example, the center point may be continually generatedbased on the random distribution through iterations such that allregions on the screen of the flat-panel display cover the grating atleast once. A gap between the screen of the flat-panel display and theraster corresponding to each grating may be a value of a constant.

For each of the gratings {R_(i)}, an N^(th) image row may be acquired byperforming sampling in a stripe image of the grating R_(i) at preset or,alternatively, desired sampling intervals. Operations S202 through S208may be performed on each image row acquired through the sampling toacquire a gap G_(r)(x; y_(r)) between the screen of the flat-paneldisplay and a raster corresponding to each image row. When operationsS202 through S208 are performed on the N^(th) image row acquired throughthe sampling, gap values: G₁(x; y₁), G₂(x; y₂), . . . , G_(r)(x; y_(r)),. . . , G_(N)(x; y_(N)) between the flat-panel display and a group ofrasters may be acquired. Also, G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N may becalculated and an x-directional average value may be calculated based onG(x). Through this, a gap G_(i) between the screen of the flat-paneldisplay and the raster corresponding to the grating R_(i) may beacquired.

The gap G(x, y) between the screen of the flat-panel display and theraster corresponding to, the entire screen of the flat-panel display maysatisfy Equation 10.

$\begin{matrix}{{G\left( {x,y} \right)} = {\left( {1/N_{a}} \right)*{\sum\limits_{i = 1}^{N_{s}}\left\lbrack {{a\left( {x,y,i} \right)}*G_{i}} \right\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 10} \right\rbrack\end{matrix}$

If [x, y]∈R_(i), a(x,y,i)=1. If not [x, y]∈R_(i), a(x,y,i)=0 andN_(a)=Σ_(i=1) ^(N) ^(s) a(x,y,i). In G(x, y), (x, y) may be coordinatesof a position of a predetermined or, alternatively, desired point on thescreen of the flat-panel display.

Scheme 3

A group of sampling points may be acquired through a sampling performedon the screen of the flat-panel display, and a grating may be generatedbased on each of the sampling points as a center point. Through this, aplurality of gratings {R_(pk)} may be acquired. Here, p is a value of 1through N_(p) and k is a value of 1 through N_(k). As illustrated inFIG. 13, a gap between center points of neighboring gratings may beequalized. The neighboring gratings may separate from each other andalso overlap each other. A gap between the screen of the flat-paneldisplay and the raster corresponding to each of the gratings may be avalue of a constant.

For each of the gratings {R_(pk)}, an N^(th) image row may be acquiredby performing sampling in a stripe image of the grating R_(pk) at presetor, alternatively, desired sampling intervals. Operations S202 throughS208 may be performed on each image row acquired through the sampling toacquire a gap G_(r)(x; y_(r)) between the screen of the flat-paneldisplay and a raster corresponding to each image row. When operationsS202 through S208 are performed on the N^(th) image row acquired throughthe sampling, gap values: G₁(x; y₁), G₂ (x; y₂), . . . , G_(r)(x;y_(r)), . . . , G_(N) (x; y_(N)) between the flat-panel display and agroup of rasters may be acquired. Also, G(x)=Σ_(r=1) ^(N)G_(r)(x;y_(r))/N may be calculated and an x-directional average value may becalculated based on G(x). Through this, a gap G_(pk) between the screenof the flat-panel display and the raster corresponding to the gratingR_(pk) may be acquired.

By performing interpolation on the three-element set {[x_(pk), y_(pk),G_(pk)]}, the gap G(x, y) between the flat-panel display and the rastercorresponding to the entire screen of the flat-panel display may beacquired. Here, G(x, y) may be one consecutive two-dimensional (2D)function, and (x, y) denotes positional coordinates of a predeterminedor, alternatively, desired point on the screen of the flat-paneldisplay. In a predetermined or, alternatively, desired element [x_(pk),y_(pk), G_(pk)] of the three-element set {[x_(pk), y_(pk), G_(pk)]},[x_(pk), y_(pk)] denotes positional coordinates of a center point of thegrating R_(pk) on the screen of the flat-panel display, and G_(pk)denotes a gap between the screen of the flat-panel display and a rastercorresponding to the grating R_(pk) a value obtained using the functionof G(x, y) acquired through the interpolation on a predetermined or,alternatively, desired interpolation point, for example, a samplingpoint may be the same as a value of the gap between the screen of theflat-panel display and a raster corresponding to the interpolation pointin the three-element set {[x_(pk), y_(pk), G_(pk)]}. For example, ifx=X_(pk), and if y=_(pk), G(x, y)=G_(pk).

In the aforementioned three schemes, A_(b) in Equation 6,P_(x)=P_(b)/cos(A_(b)), may be calculated as further described below.

When a raster rotation angle is unknown, the raster rotation angle maybe estimated. When it is assumed that an angle between a raster axis anda vertical direction of the screen is A_(b), A_(b) may be obtained usingEquation 11 as below.A _(b) =a tan [((P ₁(y)/T _(r)(y))+(P _(r)(y)/T _(sr)(y))−(P _(r)(y)/T_(c)(y)))/(((1/T _(c)(y))−(1/T _(r)(y)))*y)]  [Equation 11]

In Equation 11, P_(l)(y) denotes a phase position of a periodic signalcorresponding to an image row having a vertical coordinate y in thecalibration stripe image, T_(c)(y) denotes a period of a period functioncorresponding to the image row having the vertical coordinate y in thecalibration stripe image, T_(r)(y) denotes a period of a signalcorresponding to the image row having the vertical coordinate y in anobservation stripe image, P_(r)(y) denotes a phase position of thesignal corresponding to the image row having the vertical coordinate yin the observation stripe image, and T_(sr)(y) denotes a period in whichthe capturing device penetrates the raster and sampling is performed onthe screen of the flat-panel display,Tsr(y)=(T_(r)(y)−T_(c)(y))/T_(r)(y)*T_(c)(y)). In this example, acalculation accuracy of A_(b) may increase using an average valueacquired through a calculation performed on a plurality of columns underan assumption about a change in y.

In operation 106, the stereoscopic image corrector may correct thestereoscopic image displayed on the naked-eye 3D display based on theraster parameter calculated in operation 104.

For example, when the raster parameter calculated in operation 104 is agap between the raster and the screen of the flat-panel display, inoperation 106, a light beam model of the naked-eye 3D display may beacquired by computing a light beam corresponding to each pixel on theflat-panel display based on the gap G(x, y) between the screen of theflat-panel display and the raster calculated in operation 104. What thelight beam model indicates may be a 3D light beam corresponding to eachpixel on the flat-panel display penetrating the raster toward a userobservation space. The naked-eye 3D display may correct a stereoscopicimage error due to a raster transformation through a rendering or alight field image conversion, thereby generating an enhancedstereoscopic image.

Based on another type of raster, such stereoscopic image may include anumber of viewpoints differing for each image. For example, a binocularstereoscopic angle image may include left and right viewpoints. A prismlens or a slot raster-based stereoscopic image may include a few, forexample, tens of viewpoints or less distributed in a horizontaldirection. Also, a lens array raster-based stereoscopic image mayinclude tens of hundreds of viewpoints distributed in a spatial region.

The foregoing method may be applicable to a naked-eye 3D displayincluding a flat-panel display and a raster. For example, the method maybe performed by controlling the flat-panel display to display a stripeimage, capturing a stripe image displayed after the stripe imagedisplayed on the flat-panel display penetrates the raster, calculating araster parameter of the naked-eye 3D display based on the capturedstripe image, adjusting a method of generating an image in theflat-panel display based on the calculated raster parameter, andcorrecting a stereoscopic image displayed on the naked-eye 3D display.Through this, a quality of the stereoscopic image displayed on thenaked-eye 3D display may increase and a quality of a stereoscopic imageviewed by a user may also increase.

Also, a predetermined or, alternatively, desired stripe image may beoutput by the flat-panel display. Each image row of the stripe image maybe a periodic signal having an equal wavelength. The periodic signal mayhave a change in brightness in a wavelength of each period and eachimage row may have a periodic signal of a predetermined or,alternatively, desired frequency. Thus, a measurable image used toincrease a local error through a mole stripe phenomenon may begenerated. Also, since high definition image is to be captured using ageneral capturing device, for example, a camera in a normal viewingdistance, a user may not need to capture in a short distance and adifficulty in capturing may also be alleviated.

When the raster parameter is equal to the gap between the raster and thescreen of the flat-panel display, a gap function of the raster and thescreen of the flat-panel display may be acquired using the methoddescribed in the foregoing example. A gap value corresponding to eachpixel of the flat-panel display may be acquired. The aforementionedmethod may be applicable to a situation in which gaps between rasterscorresponding to different pixels on the flat-panel display and thescreen of the flat-panel display are different from one another, and asituation in which a dynamic change occurs in the gaps between therasters and the flat-panel display. For example, a deformation occurringwhen a material of the raster is expanded due to a heat or compressed bya pressure may cause a change in the gap between the raster and thescreen of the flat-panel display. Thus, the method of calculating a gapbetween the raster and the screen of the flat-panel display may bewidely applicable and suitable for an actual situation.

Hereinafter, an apparatus for correcting an image error of the naked-eye3D display by applying the aforementioned method will be described.

Referring to FIG. 15, an apparatus 300 may be an apparatus forcorrecting an image error of a naked-eye 3D display. As is illustratedin FIG. 15, the apparatus 300 may include a display controller 301, animage rectifier 302, a raster parameter calculator 303, and astereoscopic image corrector 304. The display controller 301 may controlthe flat-panel display to display a stripe image. The image rectifier302 may rectify an image including a stripe image captured by the rasterparameter calculator 303 based on the captured stripe image beforecalculating a raster parameter of a naked-eye 3D display. The rasterparameter calculator 303 may calculate the raster parameter of thenaked-eye 3D display based on the captured stripe image such that thecaptured stripe image corresponding to the stripe image displayed on theflat-panel display is displayed after penetrating the raster. Thestereoscopic image corrector 304 may correct a stereoscopic imagedisplayed on the naked-eye 3D display based on the raster parametercalculated by the raster parameter calculator 303.

According to at least one example embodiment, the apparatus 300 mayinclude or be implemented by one or more circuits or circuitry (e.g.,hardware) specifically structured to carry out and/or control some orall of the operations described in the present disclosure as beingperformed by the apparatus 300 (or an element thereof). According to atleast one example embodiment, the apparatus 300 may include or beimplemented by a memory and one or more processors executingcomputer-readable code (e.g., software and/or firmware) that is storedin the memory and includes instructions for causing the one or moreprocessors to carry out and/or control some or all of the operationsdescribed herein as being performed by the apparatus 300 (or an elementthereof). According to at least one example embodiment, the apparatus300 may be implemented by, for example, a combination of theabove-referenced hardware and one or more processors executingcomputer-readable code.

Further, according to at least some example embodiments, any or all ofthe display controller 301, image rectifier 302, raster parametercalculator 303, stereoscopic image corrector 304, and elements thereofmay be implemented by one or both of the above-referenced (i) hardwareand (ii) one or more processors executing computer-readable code.

According to at least some example embodiments, each of the one or moreprocessors may be a hardware-implemented data processing device havingcircuitry that is physically structured to execute desired operationsincluding, for example, operations represented as code and/orinstructions included in a program. Examples of the above-referencedhardware-implemented data processing device include, but are not limitedto, a microprocessor, a central processing unit (CPU), a processor core,a multi-core processor; a multiprocessor, an application-specificintegrated circuit (ASIC), and a field programmable gate array (FPGA).Processors executing program code are programmed processors, and thus,are special-purpose computers.

According to at least some example embodiments,

Each image row of the stripe image displayed on the flat-panel displaymay have the same wavelength of a period function, and a wavelength ofeach period function may have a change in brightness.

S1(x, y) corresponding to the stripe image displayed on the flat-paneldisplay may satisfy the following equations:S1(x,y)=A1*0.5*[sin(W_(c)*(x−P1))+1] where x denotes a horizontalcoordinate of a pixel of the stripe image on a screen of the flat-paneldisplay, y denotes a vertical coordinate of the pixel, A1 denotes anamplitude of the stripe image, and P1 denotes an error in the stripeimage; W_(c)=2π/T_(c), T_(c)=(T_(o)*T_(b))/(T_(o)+T_(b)) where T_(b)denotes a sampling period of the raster on the screen of the flat-paneldisplay; T_(min)<T_(o)<M*T_(min) where M is a predetermined or,alternatively, desired constant; andT_(min)=2*D_(v)*tan(A_(m)/2)*P_(m)/R_(m) where D_(v) denotes a viewingdistance of the naked-eye 3D display, A_(m) denotes a horizontal angleof a capturing device used for capturing, P_(m) denotes a number ofpixels in a gap between stripes to be extracted during an imageprocessing, and R_(m) denotes a horizontal pixel resolution of thecapturing device.

The rectified image and an unrectified image satisfy an equationu*[x_(s),y_(s),l]^(T)=H*[x_(i),y₁,l] where u denotes a standardizationfactor, P_(i)=[x_(i),y_(i)] is coordinates of a predetermined or,alternatively, desired pixel of the unrectified image,P_(s)=[x_(s),y_(s)] is coordinates of a pixel of the rectified imagecorresponding to the predetermined or, alternatively, desired pixel ofthe unrectified image, and H denotes a homographic transformationmatrix.

Referring to FIG. 16, the raster parameter calculator 303 may include animage row sampler 3031, a local period function acquirer 3032, a gapcalculator 3033, and a fitting unit 3034. The image row sampler 3031 mayacquire at least two image rows by performing sampling in a stripe imageof an image rectified by the image rectifier 302 at preset or,alternatively, desired sampling intervals. The local period functionacquirer 3032 may acquire a local period function T_(r)(x; y_(r)) of asignal corresponding to an r^(th) image row acquired by the image rowsampler 3031 through the sampling. In T_(r)(x; y_(r)), x denotes ahorizontal coordinate on the screen of the flat-panel display, y_(r)denotes a vertical coordinate of the r^(th) image row on the screen ofthe flat-panel display, r is a value of 1 through N, and N denotes atotal number of image rows acquired through the sampling. The gapcalculator 3033 may calculate G_(r)(x; y_(r)) corresponding to a gapbetween the screen of the flat-panel display and a raster correspondingto the r^(th) image row acquired by the image row sampler 3031 throughthe sampling, and G_(r)(x; y_(r)) may satisfy the following equations:G_(r)(x; y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotesa distance between the screen of the flat-panel display and thecapturing device, P_(x) denotes a horizontal raster interval, and Tsr(x;y_(r)) is a period change function for which the capturing deviceperform sampling by penetrating the raster relative to the screen of theflat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row. The fitting unit 3034 may acquire a gapG(x, y) between the raster and the flat-panel display by performingfitting based on a three-element set {[x_(c),y_(r),G_(r)(x; y_(r))]}. Ina predetermined or, alternatively, desired element [x_(c),y_(r),G_(r)(x;y_(r))] of the three-element set {[x_(c),y_(r),G_(r)(x; y_(r))]},[x_(c), y_(r)] denotes coordinates of a pixel on the screen of theflat-panel display and G_(r)(x; y_(r)) denotes a gap between the screenof the flat-panel display and the raster corresponding to the pixel onwhich the gap calculator 3033 has performed calculation.

Referring to FIG. 17, the raster parameter calculator 303 may include adivider 3035, a grating gap calculator 3037, and an overall gapcalculator 3038. The divider 3035 may divide the screen of theflat-panel display into at least two neighboring gratings {R_(ij)}having the same size, i being a value of 1 through N_(r) and j being avalue of 1 through N_(c). Here, N_(r) denotes a number of rows of agrating acquired through a division, and N_(c) denotes a number ofcolumns of the grating. The grating gap calculator 3037 may calculate agap G_(ij) between the screen of the flat-panel display and a raster ofthe grating using a predetermined or, alternatively, desired method foreach of the gratings {R_(ij)} acquired through the division performed bythe divider 3035, G_(ij) being a constant. G(x, y) corresponding to thegap between the flat-panel display and the raster of the naked-eye 3Ddisplay calculated by the overall gap calculator 3038 may satisfy anequation “G(x, y)=G_(ij), [x, y]∈R_(ij)”. The predetermined or,alternatively, desired method may include an operation of acquiring atleast two image rows by sampling a stripe image corresponding to thegratings and the rectified image at preset or, alternatively, desiredsampling intervals, an operation of acquiring a local period functionT_(r)(x; y_(r)) of a signal corresponding to an r^(th) image rowacquired through the sampling, wherein, in T_(r)(x; y_(r)), x denotes ahorizontal coordinate on the screen of the flat-panel display, y_(r)denotes a vertical coordinate of the r^(th) image row on the screen ofthe flat-panel display, r is a value of 1 through N, and N denotes atotal number of image rows acquired through the sampling, an operationof calculating G_(r)(x; y_(r)) corresponding to a distance between theflat-panel display and a raster corresponding to the r^(th) image row,G_(r)(x; y_(r)) satisfying the following equations: G_(r)(x;y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotes adistance between the screen of the flat-panel display and the capturingdevice, P_(x) denotes a horizontal raster interval, and Tsr(x; y_(r)) isa period change function for which the capturing device performssampling by penetrating the raster relative to the screen of theflat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and an operation of calculatingG(x)=Σ_(r=1) ^(N)(x; y_(r))/N and acquiring G_(ij) by calculating anx-directional average value using G(x).

Referring to FIG. 18, the raster parameter calculator 303 may include agrating generator 3036, the grating gap calculator 3037, and the overallgap calculator 3038.

The grating generator 3036 may generate a grating corresponding to agrating center point gradually and iteratively such that all regions onthe screen of the flat-panel display cover the grating at least once.The center point may be generated based on a predetermined or,alternatively, desired random distribution and a size of the grating maybe determined in advance. The grating gap calculator 3037 may calculateG_(i) corresponding to a gap between the screen of the flat-paneldisplay and a raster of the grating using a predetermined or,alternatively, desired method for each of the gratings R_(ij) generatedby the grating generator 3036. Here, G_(ij) is a constant, i is a valueof 1 through N_(s), and N_(s) denotes a total number of grating. G(x, y)corresponding to a gap between the flat-panel display and the raster ofthe naked-eye 3D display calculated by the overall gap calculator 3038may satisfy an equation “G(x, y)=(1/N_(a))*Σ_(i=1) ^(N) ^(s)[a(x,y,i)*G_(i)]. In this equation, if [x, y]∈R_(i), a(x,y,i) is 1, andif not [x, y]∈R_(i), a(x,y,i) is zero and N_(a)=Σ_(i=1) ^(N) ^(s)a(x,y,i). Also, an operation of acquiring at least two image rows byperforming sampling in a stripe image corresponding to the grating andthe rectified image at preset or, alternatively, desired samplingintervals, an operation of acquiring a local period function T_(r)(x;y_(r)) of a signal corresponding to an r^(th) image row acquired throughthe sampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontalcoordinate on the screen of the flat-panel display, y_(r) denotes avertical coordinate of the r^(th) image row on the screen of theflat-panel display, r is a value of 1 through N, and N denotes a totalnumber of image rows acquired through the sampling, an operation ofcalculating G_(r)(x; y_(r)) corresponding to a gap between theflat-panel display and a raster corresponding to the r^(th) image row,G_(r)(x; y_(r)) satisfying the following equations: G_(r)(x;y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotes adistance between the screen of the flat-panel display and the capturingdevice, P_(x) denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperform sampling by penetrating the raster relative to the screen of theflat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row, and an operation of calculatingG(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring G_(i) by calculating anx-directional average value using G(x) may be performed.

In one example, the raster parameter calculator 303 may also include thegrating generator 3036, the grating gap calculator 3037, and the overallgap calculator 3038. The grating generator 3036 may acquire at least twosampling points by performing sampling on the screen of the flat-paneldisplay and generate a grating in a predetermined or, alternatively,desired size based on each of the sampling points as a center point. Thegrating gap calculator 3037 may calculate G_(pk) corresponding to a gapbetween the screen of the flat-panel display and a raster of the gratingusing a predetermined or, alternatively, desired method with respect toeach grating R_(pk) generated by the grating generator 3036. Here,G_(pk) is a constant, p is a value of 1 through N_(p), k is a value of 1through N_(k), N_(p) denotes a number of rows in the grating, and N_(k)denotes a number of columns in the grating. The overall gap calculator3038 may acquire G(x, y) corresponding to a gap between the flat-paneldisplay and the raster of the naked-eye 3D display through aninterpolation of a three-element set {[x_(pk). y_(pk), G_(pk)]}. In thethree-element set {[x_(pk). y_(pk), G_(pk)]}, a predetermined or,alternatively, desired element [x_(pk), y_(pk)] represents coordinatesof a center point of the grating R_(pk) on the screen of the flat-paneldisplay and G_(pk) denotes a gap between a raster in the grating R_(pk)and the screen of the flat-panel display. The overall gap calculator3038 may acquire at least two image rows by performing sampling in astripe image corresponding to the grating and the rectified image atpreset or, alternatively, desired sampling intervals, and acquire alocal period function T_(r)(x; y_(r)) of a signal corresponding to anr^(th) image row acquired through the sampling. In T_(r)(x; y_(r)), xdenotes a horizontal coordinate on the screen of the flat-panel display,y_(r) denotes a vertical coordinate of the r^(th) image row on thescreen of the flat-panel display, r is a value of 1 through N, and Ndenotes a total number of image rows acquired through the sampling.G_(r)(x; y_(r)) corresponding to a gap between the flat-panel displayand a raster corresponding to the r^(th) image row, G_(r)(x; y_(r)) maysatisfy the following equations: G_(r)(x;y_(r))=D_(cam)*(1−(P_(x)/Tsr(x; y_(r)))) where D_(cam) denotes adistance between the screen of the flat-panel display and the capturingdevice, P_(x) denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; and Tsr(x; y_(r))=T_(c)(y_(r))*T_(r)(x;y_(r))/(T_(r)(x; y_(r))−T_(c)(y_(r))) where T_(c)(y_(r)) denotes aperiod of the r^(th) image row. The overall gap calculator 3038 may alsocalculate “G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N” and acquire G_(pk) bycalculating an x-directional average value using G(x).

A scheme of acquiring a local period function of a signal correspondingto an image row may include a scheme of acquiring peaks of the signalcorresponding to the image row and calculating a number of pixels Numincluded in a gap between neighboring peaks, a scheme of setting acalculated distance between neighboring peaks to be “Num*Ws/PixNum”. In“Num*Ws/PixNum”, Ws denotes a width of a raster area corresponding to asampled stripe image, and PixNum denotes a number of pixels in the imagerow. Also, the scheme of acquiring a local period function of a signalcorresponding to an image row may include a scheme of acquiring a localperiod function T_(r)(x; y_(r)) of the signal corresponding to the imagerow by performing fitting on a distance between neighboring peaks.

Referring to FIG. 19, the stereoscopic image corrector 304 may include alight beam model acquirer 3041 and a stereoscopic image generationcontroller 3042. The light beam model acquiring unit 3041 may acquire alight beam model of a naked-eye 3D display based on the calculatedraster parameter calculated by the raster parameter calculator 303. Thestereoscopic image generation control unit 3042 may control thenaked-eye 3D display to generate a stereoscopic image using the lightbeam model acquired by the light beam model acquiring unit 3041.

As discussed in the foregoing examples, the following effects may beachieved.

The examples may be applicable to a naked-eye 3D display including aflat-panel display and a raster. For example, the method may beperformed by controlling the flat-panel display to display a stripeimage, capturing a stripe image displayed after the stripe imagedisplayed on the flat-panel display penetrates the raster, calculating araster parameter of the naked-eye 3D display based on the capturedstripe image, adjusting a method of generating an image in theflat-panel display based on the calculated raster parameter, andcorrecting a stereoscopic image displayed on the naked-eye 3D display.Through this, a quality of the stereoscopic image displayed on thenaked-eye 3D display may increase and a quality of a stereoscopic imageviewed by a user may also increase.

Also, a predetermined or, alternatively, desired stripe image may beoutput by the flat-panel display. Each image row of the stripe image maybe a periodic signal having an equal wavelength. The periodic signal mayhave a change in brightness in a wavelength of each period and eachimage row may have a periodic signal of a predetermined or,alternatively, desired frequency. Thus, a measurable image used toincrease a local error through a mole stripe phenomenon may begenerated. Also, since high definition image is to be captured using ageneral capturing device, for example, a camera in a normal viewingdistance, a user may not need to capture in a short distance and adifficulty in capturing may also be alleviated.

When the raster parameter is equal to the gap between the raster and thescreen of the flat-panel display, a gap function of the raster and thescreen of the flat-panel display may be acquired using the methoddescribed in the foregoing example. A gap value corresponding to eachpixel of the flat-panel display may be acquired. The aforementionedmethod may be applicable to a situation in which gaps between rasterscorresponding to different pixels on the flat-panel display and thescreen of the flat-panel display are different from one another, and asituation in which a dynamic change occurs in the gaps between therasters and the flat-panel display. For example, a deformation occurringwhen a material of the raster is expanded due to a heat or compressed bya pressure may cause a change in the gap between the raster and thescreen of the flat-panel display. Thus, the method of calculating a gapbetween the raster and the screen of the flat-panel display may bewidely applicable and suitable for an actual situation.

The units and/or modules described herein may be implemented usinghardware components and software components. For example, the hardwarecomponents may include microphones, amplifiers, band-pass filters, audioto digital convertors, and processing devices. A processing device maybe implemented using one or more hardware device configured to carry outand/or execute program code by performing arithmetical, logical, andinput/output operations. The processing device(s) may include aprocessor, a controller and an arithmetic logic unit, a digital signalprocessor, a microcomputer, a field programmable array, a programmablelogic unit, a microprocessor or any other device capable of respondingto and executing instructions in a defined manner. The processing devicemay run an operating system (OS) and one or more software applicationsthat run on the OS. The processing device also may access, store,manipulate, process, and create data in response to execution of thesoftware. For purpose of simplicity, the description of a processingdevice is used as singular; however, one skilled in the art willappreciated that a processing device may include multiple processingelements and multiple types of processing elements. For example, aprocessing device may include multiple processors or a processor and acontroller. In addition, different processing configurations arepossible, such a parallel processors.

The software may include a computer program, a piece of code, aninstruction, or some combination thereof, to independently orcollectively instruct and/or configure the processing device to operateas desired, thereby transforming the processing device into a specialpurpose processor. Software and data may be embodied permanently ortemporarily in any type of machine, component, physical or virtualequipment, computer storage medium or device, or in a propagated signalwave capable of providing instructions or data to or being interpretedby the processing device. The software also may be distributed overnetwork coupled computer systems so that the software is stored andexecuted in a distributed fashion. The software and data may be storedby one or more non-transitory computer readable recording mediums.

The methods according to the above-described example embodiments may berecorded in non-transitory computer-readable media including programinstructions to implement various operations of the above-describedexample embodiments. The media may also include, alone or in combinationwith the program instructions, data files, data structures, and thelike. The program instructions recorded on the media may be thosespecially designed and constructed for the purposes of exampleembodiments, or they may be of the kind well-known and available tothose having skill in the computer software arts. Examples ofnon-transitory computer-readable media include magnetic media such ashard disks, floppy disks, and magnetic tape; optical media such asCD-ROM discs, DVDs, and/or Blue-ray discs; magneto-optical media such asoptical discs; and hardware devices that are specially configured tostore and perform program instructions, such as read-only memory (ROM),random access memory (RAM), flash memory (e.g., USB flash drives, memorycards, memory sticks, etc.), and the like. Examples of programinstructions include both machine code, such as produced by a compiler,and files containing higher level code that may be executed by thecomputer using an interpreter. The above-described devices may beconfigured to act as one or more software modules in order to performthe operations of the above-described example embodiments, or viceversa.

A number of example embodiments have been described above. Nevertheless,it should be understood that various modifications may be made to theseexample embodiments. For example, suitable results may be achieved ifthe described techniques are performed in a different order and/or ifcomponents in a described system, architecture, device, or circuit arecombined in a different manner and/or replaced or supplemented by othercomponents or their equivalents. Accordingly, other implementations arewithin the scope of the following claims.

What is claimed is:
 1. A method of correcting an image error in anaked-eye three-dimensional (3D) display, the method comprising:controlling a flat-panel display displaying a calibration stripe imagesuch that, for each row from among a plurality of rows of thecalibration stripe image, brightness values of pixels along a length ofthe row vary in accordance with a periodic waveform; obtaining, as acaptured stripe image, a captured observation stripe image, theobservation stripe image being an image resulting from the calibrationstripe image passing through a raster provided on a surface of theflat-panel display; calculating a raster parameter of the naked-eye 3Ddisplay based on the captured stripe image; and correcting astereoscopic image displayed on the naked-eye 3D display based on thecalculated raster parameter, wherein the naked-eye 3D display includesthe flat-panel display and the raster.
 2. The method of claim 1, whereinthe periodic waveform has a uniform wavelength.
 3. The method of claim1, wherein S1(x, y) corresponding to the calibration stripe imagesatisfies the following equations:S1(x,y)=A1*0.5*[sin(W _(c)*(x−P1))+1] where x denotes a horizontalcoordinate of a pixel of the calibration stripe image on a screen of theflat-panel display, y denotes a vertical coordinate of the pixel, A1denotes an amplitude of the calibration stripe image, and P1 denotes anerror in the calibration stripe image;W _(c)=2π/T _(c) ,T _(c)=(T _(o) *T _(b))/(T _(o) +T _(b)) where Tbdenotes a sampling period of the raster on the screen of the flat-paneldisplay;T _(min) <T _(o) <M*T _(min) where M is a constant; andT _(min)=2*D _(v)*tan(A _(m)/2)*P _(m) /R _(m) where Dv denotes aviewing distance of the naked-eye 3D display, Am denotes a horizontalangle of a capturing device used for capturing, Pm denotes a number ofpixels in a gap between stripes to be extracted during an imageprocessing, and Rm denotes a horizontal pixel resolution of thecapturing device.
 4. The method of claim 1, wherein the calculating ofthe raster parameter based on the captured stripe image further includesrectifying an image including the captured stripe image and calculatingthe raster parameter based on the captured stripe image.
 5. The methodof claim 4, wherein the rectified image and an unrectified image satisfythe following equation:u*[x _(s) ,y _(s),1]^(T) =H*[x _(i) ,y _(i),1]^(T) where u denotes astandardization factor, P_(i)=[x_(i), y_(i)] is coordinates of a pixelof the unrectified image, P_(s)=[x_(s), y_(s)] is coordinates of a pixelof the rectified image corresponding to the pixel of the unrectifiedimage, and H denotes a homographic transformation matrix.
 6. The methodof claim 4, wherein, when the raster parameter corresponds to a gapbetween the raster and a screen of the flat-panel display, the rasterparameter is calculated based on a first stripe image, the first stripeimage being a stripe image included in the rectified image, wherein thecalculating of the raster parameter includes: acquiring at least twoimage rows by performing sampling in the first stripe image of therectified image at first sampling intervals; acquiring a local periodfunction T_(r)(x; y_(r)) of a signal corresponding to an rth image rowacquired through the sampling, wherein, in T_(r)(x; y_(r)), x denotes ahorizontal coordinate on the screen of the flat-panel display, yrdenotes a vertical coordinate of the rth image row on the screen of theflat-panel display, r is a number having a value of 1 through N, and Ndenotes a total number of image rows acquired through the sampling;calculating a gap G_(r)(x; y_(r)) between the screen of the flat-paneldisplay and a raster corresponding to the rth image row such thatG_(r)(x; y_(r)) satisfies the following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval, and Tsr(x; y_(r)) is aperiod change function for which the capturing device performs samplingby penetrating the raster relative to the screen of the flat-paneldisplay; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andacquiring a gap G(x, y) between the raster and the flat-panel display byperforming fitting based on a three-element set {[x_(c),y_(r),G_(r)(x;y_(r))]}, wherein [x_(c), y_(r)] denotes coordinates of a pixel on thescreen of the flat-panel display and G_(r)(x; y_(r)) denotes a gapbetween the screen of the flat-panel display and the rastercorresponding to the pixel.
 7. The method of claim 4, wherein, when theraster parameter corresponds to a gap between the raster and a screen ofthe flat-panel display, the calculating of the raster parameter based onthe captured stripe image includes: dividing the screen of theflat-panel display into at least two neighboring gratings [Rij} having asame size, wherein, in Rij, i is a number having a value of 1 through Nrand j is a number having a value of 1 through Nc, Nr denotes a number ofrows of a grating acquired through a division, and Nc denotes a numberof columns of the grating; calculating a gap Gij between the screen ofthe flat-panel display and a raster of the grating using a first methodwith respect to a respective grating Rij, Gij being a constant; andcalculating a gap G(x, y) between the flat-panel display and the rasterof the naked-eye 3D display, wherein if [x, y]∈Rij, G(x, y) satisfiesthe following equation:G(x,y)=Gij, wherein the first method includes: acquiring at least twoimage rows by sampling a stripe image corresponding to the gratings andthe rectified image at first sampling intervals; acquiring a localperiod function T_(r)(x; y_(r)) of a signal corresponding to an rthimage row acquired through the sampling, wherein, in T_(r)(x; y_(r)), xdenotes a horizontal coordinate on the screen of the flat-panel display,yr denotes a vertical coordinate of the rth image row on the screen ofthe flat-panel display, r is a number having a value of 1 through N, andN denotes a total number of image rows acquired through the sampling;calculating a gap G_(r)(x; y_(r)) between the flat-panel display and araster corresponding to the rth image row, such that G_(r)(x; y_(r))satisfies the following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval, and Tsr(x; y_(r)) is aperiod change function for which the capturing device performs samplingby penetrating the raster relative to the screen of the flat-paneldisplay; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring Gij bycalculating an x-directional average value using G(x).
 8. The method ofclaim 4, wherein, when the raster parameter corresponds to a gap betweenthe raster and a screen of the flat-panel display, the calculating ofthe raster parameter based on the captured stripe image includes:generating a grating corresponding to a grating center point graduallyand iteratively such that all regions on the screen of the flat-paneldisplay cover the grating at least once, wherein the center point isgenerated based on a first random distribution and a size of the gratingis determined in advance; and calculating Gi corresponding to a gapbetween the screen of the flat-panel display and a raster of the gratingusing a first method with respect to a respective grating Rij, whereinGij is a constant, i is a number having a value of 1 through Ns, Nsdenotes a total number of gratings, and a gap G(x, y) between the rasterand the flat-panel display such that G(x, y) satisfies the followingequation:G(x,y)=(1/N _(a))*Σ_(i=1) ^(N) ^(s) [a(x,y,i)*G _(i)] where if [x,y]∈Ri, a(x,y,i) is 1, and if not [x, y]∈Ri, a(x,y,i) is zero andN_(a)=Σ_(i=1) ^(N) ^(s) a(x,y,i), wherein the first method includes:acquiring at least two image rows by performing sampling in a stripeimage corresponding to the grating and the rectified image at firstsampling intervals; acquiring a local period function T_(r)(x; y_(r)) ofa signal corresponding to an rth image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, yr denotes a verticalcoordinate of the rth image row on the screen of the flat-panel display,r is a number having a value of 1 through N, and N denotes a totalnumber of image rows acquired through the sampling; calculating a gapG_(r)(x; y_(r)) between the flat-panel display and a rastercorresponding to the rth image row, such that G_(r)(x; y_(r)) satisfiesthe following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring Gij bycalculating an x-directional average value using G(x).
 9. The method ofclaim 4, wherein, when the raster parameter corresponds to a gap betweenthe raster and a screen of the flat-panel display, the calculating ofthe raster parameter based on the captured stripe image includes:acquiring at least two sampling points by performing sampling on thescreen of the flat-panel display and generating a grating in a firstsize based on each of the sampling points as a center point; calculatingGpk corresponding to a gap between the screen of the flat-panel displayand a raster of the grating using a first method for each grating Rpk,wherein Gpk is a constant, p is a number having a value of 1 through Np,k is a number having a value of 1 through Nk, Np denotes a number ofrows in the grating, and Nk denotes a number of columns in the grating;and acquiring G(x, y) corresponding to a gap between the raster and theflat-panel display through an interpolation of a three-element set{[x_(pk),y_(pk), G_(pk)]), where [x_(pk),y_(pk)] denotes coordinates ofa center point of the grating Rpk on the screen of the flat-paneldisplay, and Gpk denotes a gap between a raster in the grating Rpk andthe screen of the flat-panel display, wherein the first method includes:acquiring at least two image rows by performing sampling in a stripeimage corresponding to the grating and the rectified image at firstsampling intervals; acquiring a local period function T_(r)(x; y_(r)) ofa signal corresponding to an rth image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, yr denotes a verticalcoordinate of the rth image row on the screen of the flat-panel display,r is a number having a value of 1 through N, and N denotes a totalnumber of image rows acquired through the sampling; calculating a gapG_(r)(x; y_(r)) between the flat-panel display and a rastercorresponding to the rth image row, G_(r)(x; y_(r)) satisfying thefollowing equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring Gpk bycalculating an x-directional average value using G(x).
 10. The method ofclaim 6, wherein a method of acquiring the local period function of thesignal corresponding to the rth image row includes: calculating a numberof pixels Num corresponding to a distance between neighboring peaksbased on peaks, each acquired from the signal corresponding to the imagerow, wherein the distance between the neighboring peaks isNum*Ws/PixNum, Ws denotes a width of a raster area corresponding to asampled stripe image, and PixNum denotes a number of pixels in the imagerow; and acquiring a local period function T_(r)(x; y_(r)) of the signalcorresponding to the image row by performing fitting on the distancebetween the neighboring peaks.
 11. An apparatus for correcting an imageerror in a naked-eye three-dimensional (3D) display, the apparatuscomprising: a flat-panel display including a screen; a raster; memorystoring computer-executable instructions; and one or more processorsconfigured to execute the computer-executable instructions such that theone or more processors are configured to, control a flat-panel todisplay a calibration stripe image such that, for each row from among aplurality of rows of the calibration stripe image, brightness values ofpixels along a length of the row vary in accordance with a periodicwaveform, obtaining, as a captured stripe image, a captured observationstripe image, the observation stripe image being an image resulting fromthe calibration stripe image passing through a raster provided on asurface of the flat-panel display; calculate a raster parameter of thenaked-eye 3D display based on the captured stripe image; and correct astereoscopic image displayed on the naked-eye 3D display based on thecalculated raster parameter.
 12. The apparatus of claim 11, wherein theone or more processors are configured to execute the computer-executableinstructions such that the one or more processors are configured suchthat the periodic waveform has a uniform wavelength.
 13. The apparatusof claim 11, wherein the one or more processors are configured toexecute the computer-executable instructions such that the one or moreprocessors are configured such that S1(x, y) corresponding to thecalibration stripe image satisfies the following equations:S1(x,y)=A1*0.5[sin(W _(c)*(x−P1))+1] where x denotes a horizontalcoordinate of a pixel of the calibration stripe image on the screen ofthe flat-panel display, y denotes a vertical coordinate of the pixel, A1denotes an amplitude of the calibration stripe image, and P1 denotes anerror in the calibration stripe image;W _(c)=2π/T _(c) ,T _(c)=(T _(o) *T _(b))/(T _(o) +T _(b)) where Tbdenotes a sampling period of the raster on the screen of the flat-panelscreen;T _(min) <T _(o) <M*T _(min) where M is a first constant; andT _(min)=2*D _(v)*tan(A _(m)/2)*P _(m) /R _(m) where Dv denotes aviewing distance of the naked-eye 3D display, Am denotes a horizontalangle of a capturing device used for capturing, Pm denotes a number ofpixels in a gap between stripes to be extracted during an imageprocessing, and Rm denotes a horizontal pixel resolution of thecapturing device.
 14. The apparatus of claim 11, wherein the one or moreprocessors are configured to execute the computer-executableinstructions such that the one or more processors are configured torectify an image including the captured stripe image and calculate theraster parameter based on the captured stripe image.
 15. The apparatusof claim 14, wherein the one or more processors are configured toexecute the computer-executable instructions such that the one or moreprocessors are configured such that the rectified image and anunrectified image satisfy the following equation:u*[x _(s) ,y _(s) ,l]^(T) =H*[x _(i) ,y _(i) ,l]^(T) where u denotes astandardization factor, P_(i)=[x_(i), y_(i)] is coordinates of a firstpixel of the unrectified image, P_(s)=[x_(s), y_(s)] is coordinates of apixel of the rectified image corresponding to the first pixel of theunrectified image, and H denotes a homographic transformation matrix.16. The apparatus of claim 14, wherein the one or more processors areconfigured to execute the computer-executable instructions such that theone or more processors are configured such that, when the rasterparameter corresponds to a gap between the raster and the screen of theflat-panel display, the one or more processors: acquire at least twoimage rows by performing sampling in first stripe image at firstsampling intervals, the first stripe image being a stripe image includedin the rectified image; acquire a local period function T_(r)(x; y_(r))of a signal corresponding to an rth image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, yr denotes a verticalcoordinate of the rth image row on the screen of the flat-panel display,r is a number having a value of 1 through N, and N denotes a totalnumber of image rows acquired through the sampling; calculate a gapG_(r)(x; y_(r)) between the screen of the flat-panel display and araster corresponding to the rth image row such that G_(r)(x; y_(r))satisfies the following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval, and Tsr(x; y_(r)) is aperiod change function for which the capturing device perform samplingby penetrating the raster relative to the screen of the flat-paneldisplay; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andperform fitting based on a three-element set {[x_(c), y_(r), G_(r)(x;y_(r))]} and acquire a gap G(x, y) between the raster and the flat-paneldisplay, wherein, in {[x_(c), y_(r), G_(r)(x; y_(r))]}, [x_(c), y_(r)]denotes coordinates of a pixel on the screen of the flat-panel displayand G_(r)(x; y_(r)) denotes a gap between the screen of the flat-paneldisplay and the raster corresponding to the pixel.
 17. The apparatus ofclaim 14, wherein the one or more processors are configured to executethe computer-executable instructions such that the one or moreprocessors are configured such that, when the raster parametercorresponds to a gap between the raster and the screen of the flat-paneldisplay, the calculating of the raster parameter based on the capturedstripe image includes: dividing the screen of the flat-panel displayinto at least two neighboring gratings {Rij} having a same size,wherein, in Rij, i is a number having a value of 1 through Nr, j is anumber having a value of 1 through Nc, Nr denotes a number of rows of agrating acquired through a division, and Nc denotes a number of columnsof the grating; calculating a gap Gij between the screen of theflat-panel display and a raster of the grating using a first method withrespect to a respective grating Rij, Gij being a constant; andcalculating a gap G(x, y) between the flat-panel display and the rasterof the naked-eye 3D display, G(x, y) being equal to Gij if [x, y]∈Rij,wherein the first method includes: acquiring at least two image rows bysampling a stripe image corresponding to the gratings and the rectifiedimage at first sampling intervals; acquiring a local period functionT_(r)(x; y_(r)) of a signal corresponding to an rth image row acquiredthrough the sampling, wherein, in T_(r)(x; y_(r)), x denotes ahorizontal coordinate on the screen of the flat-panel display, yrdenotes a vertical coordinate of the rth image row on the screen of theflat-panel display, r is a number having a value of 1 through N, and Ndenotes a total number of image rows acquired through the sampling;calculating a gap G_(r)(x; y_(r)) between the flat-panel display and araster corresponding to the rth image row, such that G_(r)(x; y_(r))satisfies the following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval, and Tsr(x; y_(r)) is aperiod change function for which the capturing device performs samplingby penetrating the raster relative to the screen of the flat-paneldisplay; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring Gij bycalculating an x-directional average value using G(x).
 18. The apparatusof claim 14, wherein the one or more processors are configured toexecute the computer-executable instructions such that the one or moreprocessors are configured such that, when the raster parametercorresponds to a gap between the raster and the screen of the flat-paneldisplay, the one or more processors: generate a grating corresponding toa grating center point gradually and iteratively such that all regionson the screen of the flat-panel display cover the grating at least once,wherein the center point is generated based on a first randomdistribution and a size of the grating is determined in advance;calculate Gi corresponding to a gap between the screen of the flat-paneldisplay and a raster of the grating using a first method with respect toa respective grating Ri, wherein Gi is a constant, i is a number havinga value of 1 through Ns, and Ns denotes a total number of grating; andcalculate a gap G(x, y) between the raster and the flat-panel displaysuch that G(x, y) satisfies the following equation:G(x,y)=(1/N _(a))*Σ_(i=1) ^(N) ^(s) [a(x,y,i)*G _(i)] where if [x,y]∈Ri, a(x,y,i) is 1, and if not [x, y]∈Ri, a(x,y,i) is zero andN_(a)=Σ_(i=1) ^(N) ^(s) a(x,y,i), wherein the first method includes:acquiring at least two image rows by performing sampling in a stripeimage corresponding to the grating and the rectified image at firstsampling intervals; acquiring a local period function T_(r)(x; y_(r)) ofa signal corresponding to an rth image row acquired through thesampling, wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinateon the screen of the flat-panel display, yr denotes a verticalcoordinate of the rth image row on the screen of the flat-panel display,r is a number having a value of 1 through N, and N denotes a totalnumber of image rows acquired through the sampling; calculating a gapG_(r)(x; y_(r)) between the flat-panel display and a rastercorresponding to the rth image row, such that G_(r)(x; y_(r)) satisfiesthe following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperform sampling by penetrating the raster relative to the screen of theflat-panel display; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=1) ^(N)G_(r)(x; y_(r))/N and acquiring Gi bycalculating an x-directional average value using G(x).
 19. The apparatusof claim 14, wherein the one or more processors are configured toexecute the computer-executable instructions such that the one or moreprocessors are configured such that, when the raster parametercorresponds to a gap between the raster and the screen of the flat-paneldisplay, the one or more processors: acquire at least two samplingpoints by performing sampling on the screen of the flat-panel displayand generate a grating in a first size based on each of the samplingpoints as a center point; calculate Gpk corresponding to a gap betweenthe screen of the flat-panel display and a raster of the grating using afirst method with respect to each grating Rpk, wherein Gpk is aconstant, p is a number having a value of 1 through Np, k is a numberhaving a value of 1 through Nk, Np denotes a number of rows in thegrating, and Nk denotes a number of columns in the grating; and acquireG(x, y) corresponding to a gap between the raster and the flat-paneldisplay through an interpolation of a three-element set {[x_(pk),y_(pk),G_(pk)]}, where [x_(pk), y_(pk)] denotes coordinates of a center pointof the grating Rpk on the screen of the flat-panel display, and Gpkdenotes a gap between a raster in the grating Rpk and the screen of theflat-panel display, wherein the first method includes: acquiring atleast two image rows by performing sampling in a stripe imagecorresponding to the grating and the rectified image at first samplingintervals; acquiring a local period function T_(r)(x; y_(r)) of a signalcorresponding to an rth image row acquired through the sampling,wherein, in T_(r)(x; y_(r)), x denotes a horizontal coordinate on thescreen of the flat-panel display, yr denotes a vertical coordinate ofthe rth image row on the screen of the flat-panel display, r is a numberhaving a value of 1 through N, and N denotes a total number of imagerows acquired through the sampling; calculating a gap G_(r)(x; y_(r)) cbetween the flat-panel display and a raster corresponding to the rthimage row, such that G_(r)(x; y_(r)) satisfies the following equations:G _(r)(x;y _(r))=D _(cam)*(1−(P _(x) /Tsr(x;y _(r)))) where Dcam denotesa distance between the screen of the flat-panel display and a capturingdevice, Px denotes a horizontal raster interval of the raster, andTsr(x; y_(r)) is a period change function for which the capturing deviceperforms sampling by penetrating the raster relative to the screen ofthe flat-panel display; andTsr(x;y _(r))=T _(c)(y _(r))*T _(r)(x;y _(r))/(T _(r)(x;y _(r))−T _(c)(y_(r))) where T_(c)(y_(r)) denotes a period of the rth image row; andcalculating G(x)=Σ_(r=n) ^(N)G_(r)(x; y_(r))/N and acquiring Gpk bycalculating an x-directional average value using G(x).
 20. The apparatusof claim 16, wherein the one or more processors are configured toexecute the computer-executable instructions such that the one or moreprocessors are configured to, calculate a number of pixels Numcorresponding to a distance between neighboring peaks based on peaks,each acquired from the signal corresponding to the image row, whereinthe distance between the neighboring peaks is Num*Ws/PixNum, Ws denotesa width of a raster area corresponding to a sampled stripe image, andPixNum denotes a number of pixels in the image row, and acquire a localperiod function T_(r)(x; y_(r)) of the signal corresponding to the imagerow by performing fitting on the distance between the neighboring peaks.